The present invention relates generally to tube bending machines, and is particularly concerned with an adjustable clamp die for a tube bending machine.
Automatic bending machines such as the machines described in U.S. Pat. Nos. 3,974,676 and 4,063,441 of Homer Eaton, assigned to Eaton-Leonard Corp., are arranged to form a series of pre-programmed bends in a length of pipe. An automatic bending machine typically has a fixed, elongated machine bed on which pipe is supported and advanced to a bend head at one end of the machine bed. The pipe at the bend head is gripped between bend and clamp dies, and these dies are rotated together to form a bend in the pipe. The dies are retracted, and the pipe is again advanced to the next bend position.
One problem with existing bend and clamp die arrangements is that, when the clamp die is relatively short, slipping of the pipe may occur when a portion of a long, straight pipe section is to be bent.